The invention relates to resilient seat suspensions and especially to suspensions of the type which utilize horizontally mounted tension springs to achieve a seat suspension having a relatively low profile. Examples of such suspensions are described in U.K. Pat. Nos. 1,230,734, 1,491,291 and 1,521,316. U.K. Pat. No. 1,230,734 is an example of a suspension where the spring acts directly on the parallel movement linkage and is mounted to it in such a manner that the spring offers less and less resistance as the linkage reaches the bottom of its stroke. The U.K. Pat. No. 1,521,316 shows a suspension which can be independent of the parallel motion linkage but could not use a specially shaped cam surface to control the spring deflection characteristics since the cam follower has varying positions relative to the cam surface corresponding to different weight adjustments. U.K. Pat. No. 1,491,291 has a cam lever which can be shaped to control the spring deflection characteristic, but the spring load must be transmitted through the parallel movement linkage and the cam shape would have to be changed if the length of one of the scissors links were to be changed. In the latter design, the springs are connected to a threaded shaft which protrudes from the front of the seat base frame and moves continually fore and aft as the suspension moves vertically. This movement would seem to present a possibility for finger pinching as would the low position of the shaft handle relative to the vehicle floor. A height adjustment mechanism is provided, but causes some loss of ride stroke at the highest positions of adjustment.